1. Field of the Invention
The invention relates to a pilot pressure switch for a furnace and a method for controlling the operation of a furnace, specifically to prevent the operation of the furnace when a pilot flame, which is intended to be continuously burning, is not burning as desired.
2. Description of the Prior Art
Many gas furnaces today utilize a continuously burning pilot flame as a source of ignition for the fuel which is burned in the furnace to provide heated air to a space, or room, to be heated. Such furnaces also typically utilize a solid state blower control device to control the operation of the main blower and a vent blower of the furnace. Typically, if the thermostat, disposed in the space, or room, to be heated, indicates that heat should be supplied to the space, or room, an electrical signal, or control voltage, is passed through the circuitry of the furnace, from the thermostat to the solid state blower control. Typically, the blower control first causes the furnace vent blower to operate. Subsequent to the furnace vent blower operating, and a conventional checking of the furnace safety controls, the burners of the furnace are ignited by the continuously burning pilot flame, and subsequently the furnace blower begins to operate to blow air through the furnace, and over the heat exchangers of the furnace, in a conventional manner.
A disadvantage associated with such prior art furnaces is that if the pilot flame, which is intended to be continuously burning, is not lit, or burning, the solid state blower control will still operate to initiate operation of the furnace vent blower and the furnace main blower in the manner previously described, even though there is no source of ignition for the gas to be burned in the burners of the furnace. For example, the pilot flame, which is intended to continuously burn, may not be burning because either the gas supply to the furnace has been interrupted, or the conventional pilot thermocouple is inoperable. It would be desirable to ensure that the furnace vent blower and main furnace blower will not operate if the pilot flame is not lit, or burning.
Accordingly, prior to the development of the present invention, there has been no pilot pressure switch for a furnace, or method for controlling the operation of a furnace, which prevents the operation of the furnace vent blower and furnace main blower, should the pilot flame not be lit, or burning. Therefore, the art has sought a pilot pressure switch and a method for controlling the operation of a furnace, which prevents the operation of the furnace vent blower and furnace main blower, if a pilot flame is not lit, or burning.